In processes of manufacturing semiconductor devices, there is a process of forming an electrode by forming a recess such as a hole or a trench in an insulating film and by embedding a silicon film such as an amorphous silicon film in the recess. In general, a chemical vapor deposition (CVD) method has been employed for a process of forming a silicon film.
However, as miniaturization of a semiconductor device has been progressed in recent years, embedment of a silicon film in a deep hole or a trench by the CVD method results in poor step coverage and thus creation of voids. If voids are created in a silicon film used as an electrode, a resistance value is increased. Therefore, a silicon film with as few voids as possible is required. This requirement is also applied to a germanium film or a silicon germanium film in addition to the silicon film.
On the contrary, there has been proposed a technique of forming a silicon film in a recess such as a hole or a trench, etching the silicon film to have a V-shaped section and then causing silicon to be embedded in the recess again. Accordingly, it is possible to achieve void-free embedment of silicon in the recess.
However, the technique of forming a silicon film in a recess such as a hole or a trench, etching the silicon film to have a V-shaped section and then causing silicon to be embedded in the recess again has problems that productivity is lowered and the process is complicated, resulting in difficulty in managing the film forming process.